Centrifugal pump



May 21, 1968 w. KING m 13,384,024

CENTRIFUGAL PUMP Filed Jan. 9, 1967 5 Sheets-Sheet 1 May 21, 1968 w.KING 3,384,024

CENTRIFUGAL PUMP Filed Jan. 9, 1967 5 Sheets-$heet 2 FEG. 5

INVENTOR. WILLIAM L. KING 36 BY ATTORNEY y 1, 1968 w. L; KING 3,384,024

CENTRIFUGAL PUMP Filed Jan. 9, 1967 5 Sheets-Sheet 3 INVENTOR.

WILLIAIYI L.. KING I '71! ATTORNEY May 21, 1968 w. KING CENTRIFUGAL PUMP5 Sheets-Sheet 4 Filed Jan. 9, 1967 FIG. I l

WILLIAM L KING INVENTOR BUCKHOR/V, BLORE, KLAROU/ST 8 SPAR/(MANATfORNEYS May 21, 1968 w. L. KING 3,384,024

CENTRIFUGAL PUMP Filed Jan. 9, 1967 5 Sheets-Sheet 5 WILLIAM L. KINGM/VENTOR BY BUC/(HORN, BLORE, KLAROU/ST a SPAR/(MAN ATTORNEYS UnitedStates Patent 3,384,024 CENTRIFUGAL PUMP William L. King, Eugene, 0reg.,assignor, by mesne assignments, to McKenzie Pump Corporation,Springfield, 0reg., a corporation of Oregon Continuation-impart ofapplication Ser. No. 447,133, Apr. 12, 1965. This application Jan. 9,1967, Ser. No. 613,715

18 Claims. (Cl. 103101) ABSTRACT OF THE DISCLOSURE In accordance withthe preferred embodiment of FIGS. 9 to the pump of the inventionincludes an outer stationary housing secured to one end of the housingof an electric motor. Within the outer housing a rotatable inner casingis fixed to the motor shaft. A fluid intake pipe extends axially throughone side wall of both the outer housing and inner casting and into themain pump chamber of the inner casing, terminating within such chamberadjacent a central inner opening in the opposite sidewall of suchcasing. Radial passages extend within the opposite sidewall from suchcentral opening and terminate adjacent the outer periphery thereof.Fluid injection poits connect the outer ends of the radial passages withouter portions of the main chamber.

A stationary pickup tube within the main chamber includes a streamlinedradial arm portion mounted on the intake pipe and a streamlinedcircumferential head portion having an intake opening at approximatelythe same distance from the rotational axis of the casing as theinjection ports. The radially inner end of the hollow pickup armcommunicates with a discharge pipe which passes from the main chamberthrough the interior of the larger intake pipe.

Thus, as the casing is rotated on the motor shaft, water or other fluidis drawn into the radial passages through the intake pipe from anexternal source. Centrifugal force urges the fluid to the outer ends ofthe radial passages where it is injected into the main chamber throughthe injection ports. Fluid at the periphery of the main chamber passesinto the head of the pickup tube under high pressure and thence into thedischarge pipe and to an outlet.

The present invention relates in general to centrifugal pumps for fluidsand more particularly to centrifugal pumps of the type having arotatable casing which impels water to a fluid collection and dischargedevice within the pump casing.

This application is a continuation in part of my prior copendingapplication Ser. No. 447,133 filed Apr. 12, 1965, entitled, CentrifugalPump and now abandoned.

Prior pumps in general, including prior centrifugal pumps have beenineflicient in pumping water at high pressures of 300 pounds per squareinch (p.s.i.) or more and have required motors of very high horsepowerto drive the same.

Multiple stage pumps, large, complex and expensive, have been usedheretofore to deliver water and other liquids in any appreciablequantity at such high pressures.

Thus there has long been a need for small, inexpensive single stagepumps capable of pumping water efliciently at high pressures and inrelatively large volumes with motors of relatively low horsepower. Tomeet the foregoing need, there has been some experimentation in the pastwith pumps of the type having a rotating casing which acts as animpeller in discharging liquid at high velocity into the interior of thecasing where a stationary or counterrotating collection devicedischarges the liquid ice from the casing under pressure. Yet a pump ofthis type that could outperform or even compete with the multiple stagepumps at high pressures has heretofore never been developed because ofvarious problems which could not be overcome and which prevented such apump from operating economically and at acceptable efficiencies andpressures. Consequently very little interest has been shown in this typeof pump in recent years, and such a pump has never been sold on acommercial scale insofar as is known.

The present invention overcomes the problems encountered previously withpumps of the rotating-casing type through a combination of uniqueimprovements of the basic pump elements which resulted from long andpainstaking experimentation. The basic improvement comprises theprovision of a stationary pickup tube within the rotatable pump casingwith the tubes pickup opening facing in a direction opposing thedirection of rotation of the casing, coupled with the provision ofradial passages within the walls of the rotating casing, whereby thedischarge pressure of the fluid to be pumped is influenced both by'thecentrifugal force imparted to it within the radial passages and by theimpact force of the fluid at the intake opening of the pickup tube. Theresult of these improvements is a pump of the rotating-casing type whichin a single stage is capable of pumping fluids under high pressures andat rates heretofore obtainable only with multiple stage pumps. Moreover,the pump of the present invention accomplishes the foregoing atefliciencies which are more than double the efiiciencies of prior highpressure pumps and with power requirements far less than those of priorhigh pressure pumps. The most significant feature of the pump of thepresent invention, however, is its simplicity, including its singlemoving part, which enables a low initial cost and maintenance-freeoperation.

Accordingly, important objects of the present invention are to provide:

(1) A single stage pump capable of pumping fluids at high pressuresheretofore obtainable practicably only with multiple stage pumps.

(2) A high pressure capable of pumping fluids at a much higherefliciency than with prior pumps.

(3) A high pressure pump having a lower power requirement than priorcomparable pumps.

(4) A pump capable of pumping water at high pressures without the usualattendant sealing problems.

(5) A pump as aforesaid of simplified construction and low cost, andrequiring a minimum of maintenance.

(6) A pump as aforesaid which is relatively small and light in weight ascompared with prior pumps having the same pressure and volumecapacities.

(7) A pump as aforesaid having rotating casing and including an improvedstationary fluid pickup element within the casing.

(8) A pump as aforesaid having an improved mounting whicfh eliminatesthe need for any bearings in the pump itsel (9) A pump capable ofpumping higher temperature fluids than most other pumps.

The above and other objects and advantages of the present invention willbecome more apparent from the following detailed description whichproceeds with reference to the accompanying drawings wherein:

FIG. 1 is a foreshortened sectional elevation of the pump and itssupporting mountings taken on the line indicated at 11 in FIG. 5;

FIG. 2 is an elevation of one side of pump taken on the line 2-2 of FIG.1 but drawn to a smaller scale;

FIG. 3 is a corresponding elevation of the other side of the pump drawnto the same scale as FIG. 2;

FIG. 4 is a fragmentary section taken on line 44 of FIG. 5 with thecasing omitted and showing the stationary pickup arm by itself, throughthe means of which the liquid is collected and discharged from the pump;

FIG. 5 is a section on line 55 of FIG. 1 with a portion of the innerplate broken away for clarity;

FIG. 6 is a fragmentary section on line 66 of FIG. 5 drawn to anenlarged scale;

FIG. 7 is a section on line 7-7 of FIG. 5;

FIG. 8 is an exploded view of the entire pump assembly drawn to asmaller scale;

FIG. 9 is a side elevational view of a modified pump in accordance withthe invention;

FIG. 10 is a right end elevational view of the pump of FIG. 9 on thesame scale as FIG. 9;

FIG. 11 is a vertical sectional view on an enlarged scale taken alongthe line 1111 of FIG. 10;

FIG. 12 is a vertical sectional view taken along the line 1212 of FIG.11 on approximately the same scale as FIG. 11;

FIG. 13 is a vertical sectional view on a larger scale than FIG. 12 andtaken along the line 1313 of FIG. 12;

FIG. 14 is a fragmentary sectional view on the same scale as FIG. 12taken along the line 1414 of FIG. 12;

FIG. 15 is a transverse sectional view taken along the line 15--15 ofFIG. 13 on the same scale as FIG. 13; and

FIG. 16 is a fragmentary vertical sectional view through the casing of afurther modification in accordance with the invention.

Referring first to FIG. 1, Form 1, 2, 3 and 8, the pump casing orhousing is rotatably mounted at opposite sides in a pair of standards 10and 11 which are secured to a suitable mounting block or bracket 12. Thepump casing 01' housing consists of a pair of circular plates 13 and 14having mating opposed peripheral cylindrical walls 13' and 14'respectively which are tightly secured together by screws or bolts 15with a suitable sealing element (not shown) interposed to form apermanent leak proof connection.

The housing plate 13 is formed with an outer circular co-axial boss 16(FIGS. 1 and 2) which has a peripheral groove to accommodate an endlessV-belt 17 through the medium of which the pump casing or housing isdriven from a suitable motor (not shown). An integral stub shaft 18extends outwardly axially from the boss 16 and is rotatably mounted inthe standard 10 by a suitable bearing assembly 19. The inside face ofthe housing plate 13 is formed'with integral pumping channels and ribsto be described later which serve as the impeller means.

The other or opposite housing plate 14 has a central circular openingwith an integral surrounding ring 20 shaped as shown in FIG. 1, with theinner wall of this ring 20 formed with an end recess for accommodating abearing assembly 21, and with an inner recess for accommodating asealing ring 22.

An intake pipe 23 (FIGS. 1, 3 and 8) has an extension member 24 (seealso FIG. 4) leading into the interior of the pump, the extension member24 having a threaded connection with the inner threaded wall of a collar23' on the intake pipe. The collar 23' and the end of the intake pipe,and therewith the extension member 24, are firmly secured in thestandard 11 by clamping means 25 (FIGS. 1, 3 and 8) provided in the topof the standard 11. The extension member 24 is formed with anintermediate thicker wall or larger external diameter portion 24 (FIGS.1 and 4). The housing plate 14 is rotatably supported on the stationaryextension member 24 by the bearing assembly 21. Thus the entire pumpcasing or housing, formed by the two plates 13 and 14, is rotatablymounted in the bearing 19 on one side and the bearing 21 on the otherside (FIG. 1).

The housing plate 13 (FIGS. 1, 5 and 8) is formed with a centralcircular recessed access opening 26 on its inside face extending beyondand around the end of the extension member 24 of the intake pipe 23. Aplugality of identical, equallyspaced, radial passages 27 on the insideface of the plate 13 lead from this recessed opening 26 to the peripheryof the inside face. The bottoms of these passages 27 slope upwardly tomeet the inside face of the plate 13 as they approach the peripheralwall 13' of the plate. The adjacent side walls of these passages 27merge where the passages start from the central recessed opening 26, asindicated at 27 in FIG. 5.

An integral radial rib 28 on the inside face of the plate 13 extendsalong the longitudinal center line of each passage 27 to the terminationof the passage at the periphery of the inside face of the plate 13. Thetop edge of each of these radial ribs 28 lies in the same plane as theinside face of the plate 13 (see also FIG. 6). Thus each rib 28 dividesthe passage in which it is located into two passages of equal size. Theinner ends of a pair of opposite radial ribs which are in alignment witheach other are continued on across the central recessed portion 26 so asto merge at the center, and another pair of aligned radial ribs whichare perpendicular to these merged pair of. ribs are also continued tothe center of the recessed opening 26, this center being indicated at 30in FIG. 5. Consequently four inner extensions 28' of the ribs meet atthe center of the recessed opening 26 and intersect each other atdegrees. The remaining ribs 28 have their inner ends terminatingapproximately at the periphery of the central recessed opening 26 ofthis plate 13.

An inner face plate 29 (FIGS. 1, 5, 6 and 8) is firmly secured on theinside face of the plate 13 and extends to the peripheral wall 13. Thisinner plate 29 has a circular central opening surrounded by a steppedoff-set portion 29, as shown in FIG. 1, the inner peripheries of whichstepped portion correspond approximately respectively to the outerperipheries of the inner end of the intake pipe extension member 24 andof the larger external diameter portion 24 of this member and thearrangement is such that an enclosed annular space is provided betweenthe member 24 and the inner plate 29 of the proper size for containing asealing ring 31. The inner plate 29 is firmly secured to the plate 13 bysuitable screws 32.

The inner plate 29 completely covers the radial passages 27 formed onthe inside face of the housing plate 13. However, near the periphery ofthe inner plate 29 a fluid injection port 33 is provided for each of thetwo portions of each of the passages 27 on opposite sides of the centerrib 28 of each passage. These pairs of ports 33 enable the liquidreceived through the intake pipe 23 and its extension member 24, whichliquid passes into the recess 26 of the plate 13 and is thence drawnthrough the passages 27 by centrifugal force as the pump casing orhousing is rotated, to be forcibly discharged through the ports 33 intothe area or chamber 34 within the pump between the iner plate 29 and theopposite housing plate 14.

The ports 33 are all identical and are similarly positioned fordischarging into the peripheral area of the main chamber 34 of the pump.However, the axial lines of these ports, instead of being perpendicularto the plane of the plate 29 or inclined forwardly in the direction ofthe rotation of the pump are inclined rearwardly in a direction oppositethe direction of rotation, as shown most clearly in FIG. 6. Inconsequence, with the rapid rotation of the pump casing, the liquid,driven by peripheral force to the ends of the radial passages 27, willbe projected through the ports 33 in the form of angled jets inclinedaway from the rotational direction of travel of the pump.

A stationary pickup element, including an arm 35, shaped substantiallyas shown in FIGS. 5, 7 and 8, is Welded to, or formed integral with, thelarge diameter portion 24' of the intake pipe extension member 24, andthis pickup arm extends generally radially close to the periphery ofmain chamber 34. The main body of stationary pickup arm 35 is curvedslightly in the direction opposite from that in which the pump rotates,as shown in FIG. 5, the direction of pump rotation being indicated bythe arrow X in this figure. In cross section arm 35 is streamlined orshaped somewhat like an ellipse pointed at both ends, as shown in FIG.7, so as to enable liquid in the main chamber 34 of the pump to movepast this portion of the stationary arm with as little friction andturbulence as possible.

The arm 35 has a head extension 35' at its outer end of flattened ovalshape in cross section (FIGS. 5, 7 and 8), which continues along theperiphery of pump chamber 34 in the direction opposite the direction ofrotation of the casing for a distance of approximately 90 degrees, orabout one-fourth of the circumferential length of the surrounding innerperipheral wall of the chamber 34. A passage 36 extends entirely alongthrough arm 35 and head extension 35, such passage being open at bothends. Where the arm 35 joins the large diameter portion 24' of theintake pipe extension 24, passage 36 is in registration with the intakeend of the inner section 37 of discharge pipe 38 (FIG. 1). The intakeend of inner section 37 of the discharge pipe extends through anaperture in the large diameter portion 24' of the member 24 to meet andmate with the end of passage 36. The adjacent end of passage 36 is ofthe same diameter as the pipe section 37, and the end of pipe section 37is rigidly secured in the large diameter portion 24 of member 24. Pipesection 37 is formed with a right angle bend and has a threadedconnection with a collar 38 on the inner end of discharge pipe 38. Thelatter extends on out through the wall of intake pipe 23, as shown,passing through an aperture in a boss 39 on the intake pipe 23 which isequipped with a sealing ring 40.

As previously indicated, rotation of the entire pump casing, and thus ofradial passages 27 and ribs 28, together with inner plate 29 definingpassages 27, causes liquid reaching the inner discharging end of themember 24 and passing into access opening 26 of plate 13, to be drawnout to the ends of passages 27 and thence to be forcibly dischargedthrough ports 33 in jets which are inclined in a direction opposite thedirection of pump rotation which is clockwise as viewed in FIG. 5. Theports 33 are located approximately the same radial distance from the'axis of rotation of the pump as the inlet end of intake passage 36 inpickup head 35'. Consequently the pickup head encounters a rapidsuccession of jets directed away from this intake end, and the fact thatthese jets are angled and directed in this manner results in the liquidbeing received into the intake end of the pickup head with less impactshock, less noise, and greater efficiency.

Furthermore the fact that pickup head 35' extends along in the peripheryof the main chamber 34 of the pump beyond the leading edge of pickup arm35, combined with the fact that intake passage 36- curves inwardly orupwardly from the periphery of the chamebr to the intake end of the pipesection 37, minimizes the shock wave and interference of the stream ofliquid forced into passage 36. The effect is that of a constant columnof water under the resulting pressure pushing through passage 36 in thepickup element and thence to the pipe section 37.

The extending of two opposed pairs of ribs 28 across the recessedopening 26 in the side plate 13, as shown at 28 in FIG. 5, providesextensions of the radial passages 27 which act to give added initialimpetus to the liquid passing into the recessed opening 26 from theintake pipe preparatory to the pasing of the liquid radially outwardlythrough passages 27, under the influence of centifugal force.

Since the fluid in the pump is under maximum pressure only at theperiphery of pump chamber 34, where the companion portions 13' and 14',forming the peripheral wall, are firmly secured together and sealed, andsince the pressure is less towards the center of the chamber 34, theusual problem in centrifugal pumps of maintaining a proper seal toresist high pressures is practically eliminated.

The pump has been shown and described as having the radial passages 27each divided in half by a center rib 28, and with each of the two halfportions provided with a peripheral discharging port 33. Nevertheless,the pump will also function very satisfactorily if the ribs 28 areentirely omitted and single narrow radial passages are substituted inplace of the double passages 27 illustrated, and with a singleperipheral port for each passage in place of the pairs of ports 33illustrated.

FIG. 9 form Referring now to FIG. 9, there is shown a modified form ofpump 50 which has gone into commercial production. This pump is mountedentirely by the electric motor 52 which drives it in a manner shown inFIG. 11 so as to eliminate the need for any bearings whatsoever in thepump itself.

The pump includes an outer stationary bell housing 54 which surrounds aninner rotatable casing 56. The bell housing includes a cover plate 58enclosing one end thereof, such plate being provided with a pressuregauge 61 and with openings 5 to reduce the pumps weight, provide accessand dissipate heat. The opposite end of the bell housing defines astepped central opening 60. Motor 52 includes a housing 62 which ismounted on a stand 64 and which has an annular flange 66 (FIG. 11) atone end thereof which bolts at 68 to the stationary bell housing of thepump at stepped central opening 60. The motor has a driveshaft 70 whichprojects through the flanged end of the motor housing and is keyed orotherwise rigidly secured at its outer end to a hub portion 72 ofrotatable pump casing 56.

Thus in the foregoing manner the stationary elements of the pump,including stationary outer casing 54, are supported directly andentirely by the motor housing. Rotatable pump casing 56, the onlyrotatable element of the pump, is supported directly by the motor shaft,which itself is, of course, rotatably mounted in bearings within themotor housing so as to obviate any need for bearings between therotatable and stationary elements of the pump itself.

As shown in FIG. 11, rotatable casing 56 defines a generally cylindricalenclosed main pump chamber 74. Casing 56 is made in two parts includinga main body portion comprising a peripheral rim 76 and one endwall 78and including an end plate defining an opposite end wall 80 which isfastened to the main body at the rim of the later by fasteners 82. Aseal 84 provides a fluid tight joint between the two sections of thecasing.

Endwall 78 of the rotatable casing has a central access opening, orrecess, 86 extending from inside the main chamber. A series of radialpassages 88 are bored into endwall 78 and into communication with accessopening 86 from the outer periphery of the casing as clearly shown inFIG. 12. The radial passages are plugged at their outer ends by plugs90, and fluid injection ports 92 connect the resulting outer ends of theradial passages with the pump chamber 74 at the outer periphery of thelatter. The radial passages are symmetrically arranged about the axis ofthe casing and about access opening 86 so as to provide the casing withproper balance as it rotates. It is desirable that the radial passagesare as long as possible for a given diameter casing to develop maximumfluid pressure at the periphery of the chamber, and therefore the radialpassages should extend as close as possible to the outer periphery ofthe casing and the center of the casing. Of course, the length of theradial passages is limited somewhat by the size of access opening 86,which must be large enough to pass fluids at rates for which the pump isdesigned.

A fluid intake pipe 94 extends from a terminal head 95 (FIGS. 9 and 10)outside the pump chamber, through a central hub portion of cover 58 andthence through a central opening 96 in endwall of the rotatable casingand through the center of pump chamber 74 to an open end immediatelyadjacent and therefore in communication with access opening 86 inendwall 78 of the rotatable casing. A fluid tight compression seal 98 atthe inner end of opening 96 prevents leakage of fluid from the chamberin the clearance space between the rotatable casing and the stationaryintake pipe. A hearing is not necessary at this point because of thepreviously described manner in which the pump is mounted on the motor.

Within the main pump chamber, a pickup element 100, including a radiallyextending arm portion 102 and a generally circumferentially extendinghead portion 104 at the outer end of the arm, is stationarily mounted onthe intake pipe by a hub-like sleeve 106 which fits over the inner endof the pipe and is secured thereto by set screws or other suitablemeans. As shown most clearly in FIG. 13, arm 102 of the pickup assemblyis hollow and open at both ends to define an internal passage 108 whichconnects at its upper end with a generally circumferentially extendingcollection passage 110 in pickup head 104. The pickup head has apreferably circular intake opening 112 at its leading end which extendsforwardly of the leading edge 113 of the arm portion and forwardly ofthe leading end of arm passage 108 for optimum efl'iciency.

The lower end of pickup arm 102 extends into a recess in mounting hub106 and furthermore is welded at 114 to the hub so as to provide astrong base mounting for the arm, necessitated by the tremendousleverage created by fluid forces acting against the upper portions ofthe arm and head. The lower end of arm passage 108 connects with theupper end of an elbow section 116 of a discharge pipe 118. Dischargepipe 118 extends within intake pipe 94 from a position inside the pumpchamber to a terminal head 95 outside the casing and bell housing forconnection to a hose or the like. The elbow section 116 extends up intoan opening with hub 106. An 0 ring seal 120 between the inner surface ofthe hub and the outer surface of the intake pipe prevents leakage offluid from the casing between these surfaces and beneath compressionseal 98. An orifice 122 through hub 106 connects the discharge passagewithin the hub to the central portion of the chamber at seal 98 so as todirect liquid at the seal and thereby lubricate the same even when thecentral portion of the chamber is not filled with liquid.

It has been found through extensive testing that the shape of the pickupelement and the size thereof in relation to the pump chamber isimportant to maintain high pump efficiency, high pressures and lowerpower requirements. For example, if the overall thickness t (FIGS. 11and of the pickup arm is too great with respect to the width W of thechamber from one endwall to the other, the arm presents such a largeobstruction to the passage of water that power requirements to drive thepump rise to impracticable levels. In this regard, a minimum spacing ofat least one thickness of the arm should be provided between the arm andeach endw-all of the chamber. Preferably, the maximum thickness t of thearm should not exceed about one-fourth the width W of the chamber, withthe arm being approximately centered in the chamber between endwalls inorder not to adversely affect the pumps efliciency to a marked degree.

Similarly, it has been found highly desirable to streamline both thepickup head and the pickup arm in the direction of fluid flow tominimize frictional resistance and turbulence and thereby maintainoptimum efficiency. As shown in FIG. 15, pickup arm 102 is generallyelliptical in cross section and pointed at both ends with at least theleading edge 113 preferably being sharpened to a knife edge so as toslice more effectively through the water.

The maximum thickness 1 of the pickup arm preferably should not exceedabout one-fourth of the overall width w of the arm. The overall width wof the arm should not be overly great, however, as an excessive widthwill increase frictional resistance and turbulence to an undesirableextent. For example, it has been found that in a pump having a mainchamber diameter of 14 inches the maximum width of the arm should notexceed about three inches to keep such friction and turbulence factorswithin acceptable levels. It has also been found that the use of two ormore pickup elements, or a pickup element in the form of a stationarydisc as used in some prior pumps of this general type, are impracticablebecause they create and excess of frictional resistance to the flow offluid within the chamber.

The pickup head 104 is also streamlined, being elongate in a directiongenerally circumferentially of the chamber and normal to arm 102. Thehead is preferably generally bullet shaped as shown in FIG. 13, taperingfrom a relatively blunt leading end to a sharp pointed trailing end 128.The head is preferably of substantially no greater diameter, orthickness, than the arm, although the head may be slightly greater inthickness due to the provision of intake opening 112. It has been foundthat if the head is not streamlined as described it can create aturbulence that will cause a buffeting at the intake opening of the headas the casing rotates, thereby affecting adversely the efficiency of thepump.

Experimentation has also shown that collection passage 110 of the pickuphead should extend forwardly of arm passage 108 for optimum pumpingpressures and efficiency, as shown in FIG. 13, and that the leading endof the head should preferably lead at least slightly leading edge 113 ofthe arm so that any turbulence or shock wave created by the arm will bedownstream from the leading end of the head as determined by thedirection of rotation of the casing.

It has been found that the efficiency of the pump increases as the leadof the head increases forwardly of the leading edge of the arm to acertain extent, provided the streamlined shape of the head is maintainedand provided that for longer head lengths the head is curved inconformity with the curvature of the periphery of the chamber as shownin FIG. 5. Nevertheless, when the head extends forwardly of arm throughan arc of greater than about 45 degrees, the head tends to vibrate andprevent any substantial increase in efliciency beyond this point.However, as indicated with respect to the FIG. 1 form of pump, the headcan extend through an arc of about degrees and still be operableprovided vibration can be held to an acceptable level.

The hub 106 which mounts arm 102 also has size limitations because ofthe resitsance and the resulting turbulence which it would otherwisecreate as fluid flows past it within the pump chamber. Yet the hub mustbe of a sufficient size to mount the arm rigidly. For example, in a pumphaving a chamber 14 inches in diameter, the hub having a cross sectionalshape as shown should not exceed about five inches in diameter andideally is about four inches in diameter.

As shown best in FIG. 14, the pump casing is rotated in a predetermineddirection as indicated by the arrow (in a counterclockwise direction asviewed in FIG. 12), and intake opening 112 of the pickup head faces inthe opposite direction to receive fluid from the chamber. The pumpoperates with its maximum efficiency when fluid injection ports 92 areangled rearwardly in a direction opposite the direction of rotation ofthe casing at an angle a to the axial plane of its associated radialpassage. If angled rearwardly at about 45 degrees as shown, theefficiency of the pump will be increased approximately five percent overthe efiicicncy when the injection ports are normal to the direction ofrotation, or to the axis of intake opening 112 in the head. In contrast,if the ports are angled in the direction of rotation, or toward intakeopening 112, the efiiciency will drop about thirty percent from what itwould be with the ports normal to the axis of the intake opening and thenoise level of operation will rise considerably. For this reason, theports should extend either normal to the axis of the intake opening orpreferably rearwardly, away from such opening.

Another factor which reduces signficantly the turbulence and butfetingcaused by the flow of fluid past the pickup head is the provision of asharp-edged intersection 130 between the outer surface of the pickuphead and a beveled inner surface 132 of the head at the leading endthereof. It is important that the sharp edged intersection be formed bybeveling the inner surface 132. rather than by beveling the outersurface of the head, for otherwise the resulting turbulence and shockwave would adversely affect the efiiciency.

Examples As an example of the results obtainable by a pump of the formshown in FIG. 9, such pump with a main pump chamber of fourteen-inchdiameter, two-inch intake passage, and a three-quarter inch dischargepassage was rotated at a speed of 3562 r.p.m. by a twenty-fivehorsepower electric motor and delivered water at a rate of thirty-fivegallons a minute at a pressure of 468 p.s.i. with a forty percentefficiency under controlled testing conditions. The same pump deliveredwater in excess of 500 p.s.i. at a rate of twenty-five gallons perminute with an efficiency of nearly thirty-five percent.

As an example of a commercial production model of a fourteen-inch pumpof the illustrated design of FIGS. 9- 15, the outside diameter of therotatable pump casing is sixteen inches, the radial passages have adiameter of thirty-seven sixty-fourths of an inch and the injectionports have a diameter of one-half inch. The Width of the main pumpchamber is approximately two inches and the overall thickness of thepickup arm is slightly less than on-half inch. The radial distance fromthe axis of the pump chamber to the outer extremity of the pickup headis six and seven-eighths inches. The overall width w of the pickup armis about two inches and the inside width of the arm passage is about oneand three-quarter inches. The pickup head is approximately two andthreequarter inches long and about one-half inch in diameter. The hubhas an outside diameter of four inches and an inside diameter of twoinches. The inside diameter of the intake pipe is approximately one andsix-tenths inches and the inside diameter of the discharge pipe isslightly in excess of four-tenths inch.

FIG. 16 form With reference to FIG. 16, there is shown a peripheralportion of a main pump chamber 74' of a modified form of pump similar tothe pump of FIG. 9 but with a retatable casing 56 having a modifiedporting 92 leading from the radial passages 88' into the periphery ofthe pump chamber. In the FIG. 16 form of casing, radial passages 88'take a right-angle bend near their outer ends and extend part way intothe rim portion 76' of the casing. The injection ports 92 of themodified pump are angled rearwardly in a direction opposite thedirection of rotation of the casing 56', as in the FIG. 9 form, the onlydifference between the porting of FIG. 14 and that of FIG. 16 being thatin the former the fluid enters the periphery of the chamber from the topof the casing rather than from an endwall thereof. The pump of FIG. 16has the usual pickup element including arm 102' and pickup head 104' asin the FIG. 9 form of the pump.

Operation Referring again to the FIG. 9 form, and particularly to FIG.11, in operation, motor 52 rotates casing 56 so that, for example, wateris drawn from a source (not shown) through intake pipe 94 into accessopening 86. Centrifugal force induced by the rotating casing forces thewater to the outer extremities of the radial passages 88 from which thewater is injected at high velocity (or high pressure if the chamber isalready filled with fluid) into pump chamber 74. Despite the rearwardinclination of the injection ports 92, the water discharged into themain chamher will flow past the pickup head in the direction of rotationof the casing due to the rotation of the casing at speeds which mayattain in excess of 3000 r.p.m. Th only purposes of the rearwardlyangled ports are to reduce the impact shock of a jet of water againstthe intake of the pickup tube and to lessen the tendency for turbulencewithin the chamber so that the pickup head will more readily inhale thewater.

In practice, it has been found that water entering the chamber willgradually completely fill the same, thereby placing a compressive forceon seal 98 to prevent leaks at this point. It has also been found thatthe efficicncy of the pump increases sharply as the casing fills andthat the maximum efiiciency is attained when the casing is completelyfull of liquid. For this reason it is recommended that the intake pipeand radial passages, injection ports and passages within the pickupelement and discharge pipe be sized so as to permit the chamber to fillduring operation, and that the casing be completely enclosed to permitthis condition to occur without loss of fluid.

However, an air vent pipe 134, shown in FIG. 11, is provided to permitair to escape from the center of the chamber as water fills the chamberfrom its periphery so that water can completely fill the chamber and thepump can operate at maximum efiiciency. The vent pipe extends from itsconnection to an orifice in hub 106, within the intake pipe to an outletend 136 (FIG. 9) at the terminal head outside the pump chamber. Theoutlet end is preferably provided with a shutoff valve 138 so that afterall air is removed from the chamber the valve can be closed to preventthe discharge of liquid from the vent tube. Of course, if the pump wereconnected to a source of water under pressure, as for example, tapwater, the vent pipe would be unnecessary because the casing could befilled with water without rotating the same, and air initially Withinthe casing would escape through the pickup tube.

After water is forced into the pickup head through its intake openingthe water travels down the arm passage and out of the pump chamberthrough discharge pipe 118, which is connected at its outer end to ahose or other conduit leading to the point of use.

The illustrated pumps can be operated at a considerably reduced pressureif desired simply by reversing the direction of the driving motor toreverse the rotation of the pump casing.

The illustrated single stage pumps are capable of delivering efiicientlylarge quantities of Water at high pressures which heretofore could onlybe attained practicably with multiple stage pumps. Their wide variety ofuses includes, for example: (1) washing off heavy equipment; (2) washingdown ships; (3) washing off electrical insulators; and (4) fireprotection. The elimination of bearings and the provision of only onemovable part, th rotating casing, all but eliminates maintenance.

Having illustrated and described several different forms of theinvention, it should be apparent to those skilled in the art that theinvention permits of modification in arrangement and detail. I claim asmy invention all such modifications as come within the true spirit andscope of the following claims.

I claim:

1. A centrifugal pump comprising:

a generally cylindrical pump casing rotatable about its central axis anddefining a closed cylindrical main pump chamber,

means defining a radial passage within one endwall of said casingextending from a central portion of said one endwall to a peripheralportion of said one endwall,

a stationary intake passage means extending through a central portion ofan opposite endwall of said casing to a position within said chamberadjacent said one endwall,

said one endwall having a central access opening connecting the interiorof said intake passage with the radially inner end of said radialpassage,

21 fluid injection port means connecting the radially outer end of saidradial passage with the interior of said chamber adjacent the peripherythereof,

a single fiuid pickup element stationarily mounted within said chamber,including a single hollow generally radial arm open at both endsextending from a central portion of said chamber toward the outerperiphery thereof and a single pickup head on the outer end of said armadjacent the outer periphery of said chamber,

said head being elongate in a direction generally normal to thegenerally radial direction of said arm and generally circumferentiallyof said chamber,

said head having an intake passage extending from an intake opening at aleading end thereof into communication with the interior of said arm,

said arm and said head being spaced from each of the opposite endwallsof said casing defining said chamber a distance equivalent to at leastthe maxi mum thickness of said arm,

said arm in transverse cross section having a streamlined generallyelliptical configuration with pointed leading and trailing edges,

and a stationary discharge passage means extending from a connectionwith the interior of said arm at the radially inner end of the latteroutwardly of said chamber through a central portion of said oppositeendwall of said casing.

2. Apparatus according to claim 1 including:

means for rotating said pump in a predetermined direction,

the leading end of said pickup head facing in a direction opposite saidpredetermined direction of rotation,

said fluid injection port being angled so as to discharge fluid intosaid chamber either in a direction normal to the direction of rotationof said casing, or in a direction generally opposite the direction ofrotation of said casing.

3. Apparatus according to claim 1 wherein the leading edge of saidpickup arm faces in a direction opposite the direction of rotation ofsaid casing and is sharpened to a knife edge.

4. Apparatus according to claim 2 wherein said pickup head isstreamlined in its direction of elongation and the leading end of saidpickup head extends forwardly of the most forward leading edge portionof said arm in a di rection opposite said predetermined direction ofrotation.

5. Apparatus according to claim 2 wherein the leading end of said pickuphead extends forwardly of the leading edge of said arm in a directionopposite said predetermined direction of rotation but through no greaterthan about 90 degrees of the arc of said chamber.

6. Apparatus according to claim 1 wherein the inner surface of saidpickup head defining said intake passage is beveled inwardly andrearwardly from a sharp intersection with an outer surface of saidpickup head at the leading end of said head so as to minimize fluidturbulence and noise at said leading end.

7. Apparatus according to claim 1 wherein the maximum thickness of saidpickup arm as measured in a direction across the width of said mainchamber between endwalls is no greater than about one-fourth the widthof said chamber.

3. Apparatus according to claim 1 wherein the maximum thickness of saidpickup arm as measured in a direction across the width of said chamberbetween endwalls is no greater than about one-fourth the width of saidarm as measured at the same level in said chamber.

9. Apparatus according to claim 1 including a fluid seal between saidstationary passage means and said casing at the central opening throughsaid opposite endwall so that said chamber can be completely filled withfluid under pressure.

10. Apparatus according to claim 1 wherein the entrance angle of saidinjection port into said chamber as measured from the axis of the intakepassage of said pickup head is greater than 90 degrees so that said portdirects Water into said chamber in a direction away from the intakeopening in said pickup head.

11. Apparatus according to claim 10 wherein said entrance angle isgreater than 90 degrees but no greater than about 150 degrees.

12. Apparatus according to claim 1 wherein there is a plurality of saidradial passages symmetrically arranged about the axis of said casing,all opening into said central opening and each having an associatedfluid injection port.

13. Apparatus according to claim 1 wherein said intake passage meanscomprises a straight intake pipe section extending through a centralopening in said opposite endwall of said casing and into communicationwith said central access opening in said one endwall and said dischargepassage means comprises a single discharge tube of smaller diameter thansaid intake tube extending from communication with said pickup arm at acentral portion of said chamber into the interior of said intake tubeand within said intake tube to a position outside said chamber,

said pickup arm being stationarily mounted on said intake tube.

14. Apparatus according to claim 1 including motor means for rotatingsaid casing,

said motor means including a motor housing having an annular flange atone end thereof and a motor shaft extending through the opening definedby said flange,

said pump including a stationary housing extending about said rotatablecasing,

first connecting means connecting said stationary housing to the annularflange of said motor housing,

and second connecting means drivingly connecting said motor shaft tosaid rotatable casing so that said shaft supports said rotatable casing,thereby eliminating the need for bearings on said pump.

15. A centrifugal pump comprising:

a generally cylindrical pump casing having a peripheral wall andopposite end'walls defining an enclosed cylindrical main pump chamber,

motor means mounting said casing for rotation about its central axis ina predetermined direction,

a plurality of radial passages in one of said endwalls extendingsymmetrically from a central access opening in said one endwall fromsaid chamber, to peripheral portions of said one endwall.

a stationary intake tube extending through a central opening in theother of said endwalls and through a central portion of said pumpchamber into communication with said central access opening in said oneend wall,

a stationary discharge tube extending within said intake tube from acentral portion of said chamber to a discharge end outside saidrotatable casing,

a single fluid pickup element stationarily mounted within said pumpchamber on said intake tube,

said pickup element including a hollow pickup arm extending generallyradially within said chamber from its mounting on said intake tube to anouter end near the outer periphery of said chamber and a fluid intakehead connected to the outer end of said arm,

said head defining an intake passage extending from an intake opening ata leading end of said head into communication with the interior of saidarm, said leading end facing in a direction opposite said predetermineddirection of rotation of said casing,

said head being elongate in a direction generally normal to the radialdirection of said arm and generally circumferentially of said chamberand having a streamlined configuration in its direction of elongation,

said arm in transverse cross section having a streamlined ellipticalsurface configuration tapering to sharp leading and trailing edges,

the ratio of the maximum thickness of said arm to the width of saidchamber from one endwall to the other being no greater than about 1 to 4and said arm being approximately centered between said endwalls withinsaid chamber,

means defining a plurality of fluid injection ports in a peripheralportion of said casing leading from the peripherally outer ends of saidradial passages into a peripheral portion of said chamber adjacent saidpickup head,

said injection ports opening into said chamber at a back angle ofgreater than 90* degrees as measured from the axis of the intake passagein said pickup head so as to discharge fluid into said chamber in adirection generally opposite said predetermined direction of rotation,

said pickup head having a leading end projecting in a direction oppositesaid direction of rotation forwardly of the most forward leading edgeportion of said pickup arm, and

means sealing the central opening in said other endwall between saidendwall and said intake tube against the passage of fluid therethroughunder pressure so that said chamber can be completely filled with fluidunder pressure.

16. A pump according to claim 1 including a vent tube extending from aninlet end in communication with a central portion of said chamber to anoutlet end outside said casing.

17. A centrifugal, pump comprising:

a generally cylindrical pump casing rotatable about its central axis anddefining a closed cylindrical main pump chamber,

means defining a radial passage within one endwall of said casingextending from a central portion of said one endwall to a peripheralportion of said one endwall,

a stationary intake passage means extending through a central portion ofan opposite endwall of said casing to a position within said chamberadjacent said one endwall,

said one endwall having a central access opening connecting the interiorof said intake passage with the radially inner end of said radialpassage,

a fluid injection port means connecting the radially outer end of saidradial passage with the interior of said chamber adjacent the peripherythereof,

a single fluid pickup element stationarily mounted within said chamber,including a single hollow generally radial arm open at both endsextending from a central portion of said chamber toward the outerperiphery thereof and a single pickup head on the outer end of said armadjacent the outer periphery of said chamber,

said head being elongate in a direction generally normal to thegenerally radial direction of said arm and generally circumferentiallyof said chamber,

said head having an intake passage extending from an intake opening at aleading end thereof into communication with the interior of said arm,

said arm in transverse cross section having a streamlined generallyelliptical configuration with pointed leading and trailing edges,

and a stationary discharge passage means extending from a connectionwith the interior of said arm at the radially inner end of the latteroutwardly of said chamber through a central portion of said oppositeendwall of said casing,

said intake opening on said head facing in a direction opposing thenormal direction of rotation of said casing so that upon rotation ofsaid casing in said normal direction, the centrifugal forces generatedby said rotation and the impact forces induced by the impact of fluidagainst said head at said intake opening are additive in their effect onthe pressure head of fluid entering the intake passage of said head.

18. A centrifugal pump comprising:

a pump casing mounted for rotation about a central axis extendingthrough said casing and having oppositc endwalls,

said casing being rotatable in a predetermined direction,

means including said casing defining an annular pump chamber,

radial passage means enclosed within an endwall of said casing, saidradial passage means radiating from a central inlet portion of saidcasing toward the outer periphery of said casing and discharging intosaid annular pump chamber at an outer peripheral portion thereof,

fluid intake passage means communicating with said central inletportion, whereby fluid entering said central inlet portion through saidfluid intake passage means does not interfere with the flow of fluidwithin said annular chamber,

fluid pickup tube means stationarily mounted within said annular chamberand extending from a central portion of said chamber radially to anouter end at an outer peripheral portion of said chamber,

means at said outer end of said pickup tube defining a fluid intakeopening,

said fluid intake opening facing in a direction opposite said normalpredetermined direction of rotation of said casing.

References Cited UNITED STATES PATENTS 3,034,443 5/ 1962 Hinrichs et al.103111 3,049,081 8/ 1962 Singelmann 103-101 3,307,485 3/1967 Logue103101 FOREIGN PATENTS 737,933 10/ 1955 Great Britain.

34,133 1/1913 Sweden.

HENRY F. RADUAZO, Primary Examiner.

